BugBrand offers a constantly expanding and mutating range of electronic sound & effect devices, all built by hand in Bristol, singly or in small batches. All designs mix experimental audio circuitry with ideas taken from the techniques of circuit bending, and bring together many different controls and playing methods to give intuitive and inspiring instruments.

Please check the homepage and shop for updates on availability!

Jump to Current Devices:
Weevils, BugCrushers, Modular, Contact Mics

Jump to Archive Devices:
Drone Machine, MiniModular System, Old BugCrushers, Weevil06, PostcardWeevil07, PostcardWeevilV2, Other Weevils,
Mutant Weevils, Circuit Bent Devices, MIDI Devices, 9v Cell Instruments, One-Off Boxes

Weevils:
Weevils are built around lofi squarewave oscillators which are quasi-ringmodulated together. Add on power starvation, body contacts and other features and you get versatile noise'n'drones, full of chaotic and analogue life..
Weevils currently come in three standard forms from big to small:
AudioWeevil, Weevil08, PostcardWeevil

AudioWeevil07

Frontpanel Layout

Block diagram

AudioWeevil07 prototype

AudioWeevil07
First batch released 31st Oct 2007
Sold out within hours..
A redesign for regular production is due sometime in 2008

The AudioWeevil has finally undergone an upgrade to 07 version.

The heart of a Weevil is the two lofi squarewave Oscs that get quasi-ringmodded together for crash'n'scream sounds. What we do with the AudioWeevil version is to take an input audio signal and turn it into a squarewave that can then replace one of the internal Weevil Oscs - so your squared input gets ringmodded with one of the internal Oscs for supremely gnarly ringmod and tremolo effects. The effect works best with monophonic sounds - guitar picking or keyboards - the sounds are extreme!

This new version ups the stakes by building in a mixer stage which allows blending of the Dry audio, Squared Audio (a very overdriven version of the dry input) and Ringmod (Weevil) output before it is passed through a powerful resonant LowPass filter. And now there's also a modulation LFO to sweep internal Osc1 and the filter cutoff. This LFO has two speed ranges (right up into audio rates which work great for filter modulation) and three waveforms - ramp, tri and sawtooth. The LFO is one of the nicest features of these new Weevils!

Another fun feature is the internal mini-amp/speaker. This allows you to make noise on the move and the sound is pretty different to what you get from the line-out, so there's possibilities for nice creative recording experiments. And it can chuck out quite a hefty sound - though, be aware that it can chomp through batteries pretty quickly when the amp is driven hard.

The touchplate is another area of great sonic-bend-potential and the engraved and tinned board features 11 touchpoints connecting to the audio input (1), Oscs (5), LFO (3) and filter (2).

Check the Frontpanel and Block diagrams to the left to get more of an idea what may be going on...

In essence, the AudioWeevil07 is capable of going from pure & clean (eg. audio input filtering with lfo modulation) to hyper-screech (eg. many other settings!). It comes in a slope-fronted plastic case with metal frontplate.

Here are two mp3s of run arounds on the AudioWeevil (no processing added) showing some of the wide ranging sounds. Pure Synth Weevil Sounds - drones, wobbles and touchplate frenzy-pops. Guitar Processing - this begins with a clean guitar running through the filter with adjustment and some all-over modulations. The squared signal dirties everything up and shows the wierd gated sound possibilities. Dry frets mix in before the Weevil sounds crash down. Gnarl, screech, stutter, blop! I didn't even use the touchplate for all this...

There's a YouTube demo video up here of the prototype in action.
More samples / videos / documents coming shortly...

Weevil08 - Green & Red
Rear view

Panel Layout & Block Diagram

Weevil08
Released Feb08

Here's the new Weevil08 - three lo-fi oscillators quasi-ringmodulated together, with PowerStarve, Filter, 9-point-TouchPlate and internal MiniAmp.

While the core Weevil circuitry is similar to the Postcard, the sonic results are quite different - for one, each Osc has a range switch for Hi tones or Lo clickety, and the output levels are much more stable due to a comparator circuit (don't worry - there's still loads of chaos within!). The combination of PowerStarve and responsive TouchPlate opens up a vast array of sounds that are played in a way unlike any other instrument. The internal MiniAmp is now a standard feature and gives a pretty different tone/response from the output jack. Plugging in a jack conveniently disconnects the internal MiniAmp.

This is a newly standardised version built with pro-PCBs for improved feel and replicatability, available in Green or Red with chunky knobs in a sprayed plastic case and running off a single 9V battery.

You can check the block diagram for details of the internal arrangement, but it may be best just to listen to the mp3 demo (11MB) that wobbles through some of the wide-ranging sounds available!

See older versions in the Weevil Archive

PostcardWeevil08
Released Dec07

The PostcardWeevil is a hyper-portable sonic world with three ring-modulated oscillators, power starvation, body contacts, line out and mini-amp, all in a package measuring just 7 x 8 cm! The design has been maturing & mutating for two years and we now arrive at the new 2008 version.

There's a vast range of sounds hidden within the little package which are coaxed out through settings of the dials and body contacts. At first the device may seem chaotic, but with practice and feel you really can play, rolling along with the unexpectedness that springs out! Everything intermodulates, so a small twist of a dial can send the sounds spinning into new areas.

Personally I really love the characterful sound from the onboard MiniAmp (and like the ethos of total portability), but there's also a mono 1/8" minijack line output (due to popular demand!). The resulting sound and behaviour is even quite different from that of the MiniAmp.

This is my first project using professional PCBs which allow greater compactness, replication and feel.

YouTube demo video here.

See also PostcardWeevil07 & PostcardWeevilV2

BugCrushers:
BugCrushers are Sample-rate Reducer pedals - I guess I confused things by naming them Crushers - just to be clear, they are not actually Bit Crusher effects! If you look at a standard BitCrush plugin you have controls for Bit Depth (thats the part I can't (yet) do - I work in analogue) and Sample Rate -- my pedals just do the second bit. That's not to say they're sonically lacking - the sound of RateReduction is very fine - at high rates you get fizzly distortionary sounds, while turning down the rate brings you into sounds quite like ring modulation (though perhaps more musical?) - really great for droning!
In technical terms the BugCrusher uses a Sample & Hold circuit running at audio rates. Sample & Hold is found in various analogue synths, but generally running at low frequencies to provide randomised voltage steps. The circuit is often fed from a pure noise source (so you've got randomness) and then clocked by an LFO.
BugCrushers currently come in three standard forms:
BugCrusher08, BabyBugCrusher, BugCrusherMicro

BugCrush08 Stomp

BugCrusher08 Desktop

Controls

Block Diagram

Crusher Eye - optional extra

BugCrusher08
New Stomp version released Apr2008

Here's the new and updated big version BugCrusher! Its a stompable unit (the first batch was desktop) with quite a complex design (check the block diagram to the left) that packs in many features -> analogue rate reduction followed by a resonant filter, plus voltage control so that rate and/or filter can be controlled with an external CV or expression pedal.

• Input preamp for guitar or line level signals - switchable Hi or Lo gain plus input level control
• Voltage controlled Crusher circuit ranging from fizzle-highs to drone-tone lows, with a large chickenhead dial for the master CrushRate, plus variable modulation depth from an external source
• Pre-filter mixer to blend the dry and crushed signals - also with switchable phase inversion on the crushed signal for a extra mixing possibilities (audio phase cancellations!)
• Voltage controlled Filter with switchable LoPass or BandPass responses and variable resonance. This has a main Cutoff dial plus variable modulation depth
• Switchable output levels for guitar amps (lo level signal) or mixing desk (hi level signal)
• External input switchable between CV or Foot Pedal, with variable modulation depth for CrushMod and/or Filter Mod - ie, you can use a standard expression pedal to change the Crush Rate or the Filter Cutoff - or both at the same time - or use a CV (standard +/- 5v) signal from an analogue synth
• Electronic true-bypass switching
• Powered by an external 15vAC plug-in power pack (supplied)
• Housed in a metal case measuring 12.5 x 12.5 x 7.5 cm

This is one of my first devices using professional PCBs - you can see some more details on the building process on the BugBlog

Click here for the instruction sheets which give some more detailed details...

Here are some sounds (slightly badly recorded with mic so there's background noise and hiss - oops - I'll try to get some direct ones soon..)
Pianet MP3
Guitar MP3
TR606 MP3

New Crusher Eye optional extra (added May08)
- this is a little light dependent control wand that plugs into the Foot Control input and allows CV modulation of the Crush / Filter by varying the amount of light.

BabyBugCrusher9volt
Released late Aug07
This design is now being redesigned for regular production.

The BugCrusher is an analogue sample-rate reducer offering a range of sounds from fizzly high-end distortion down into murky sonic depths akin to ring-modulation. The inner circuitry has been completely redesigned for this new version. The main change is that things now run off a simple 9v supply (battery or plug-in) rather than the old AC adaptor version and this change has allowed some extra features to be included too.

First up is a variable gain preamp with clean/dirty setting -- boost the signal and give it some crunch. This is followed by the audio-rate S&H circuit that forms the heart of the BugCrushing effect. After this comes a treble boost/cut controlfor tone-shaping before a final output level adjustment.

Two versions, stomp and desktop, have been made and these are both true-bypass - stomp has a chunky footswitch, desktop has a toggle switch. The two versions have the same circuitry inside, but they are laid out a bit differently - the stomp version has input on the right (guitar pedal standard) while the desktop goes from the left (which seems more logical to me). The circuit is designed for guitar level signals, but can handle line level signals (sometime with a little care, though).

Metal case with transfer labeling
Unbalanced 1/4" mono in/out
9v supply (<10mA current draw)
- internal battery (remove base to replace)
- 9v DC socket - standard Boss-style centre negative 2.1mm

Sound examples
- Guitar line - clean crushing and then adding in some crunch
- Synth chimes - crushing works well on rich bell tones etc.
- Synth beat drums - clean then crushed then crunch-crushed
- Mono/poly arps - hear how a resonant input signal can give a vocal-y warble.

Instruction pdf

See also BugCrushers Archive

BugCrusherMicro
Production vers1.2 update released Apr2008

The new Micro squeezes the lovely sample-rate-reductions of the BugCrusher line into the most compact form yet - just 120 x 65 x 40mm (about the size of MXR pedals).

A single dial sets the Rate for sounds from fizzly-fuzz highs to distruct-o-gurgle lows. There's no need for level controls - the signal going in is neither amplified nor attenuated. The Micro works well on low level signals (such as guitar) or line level signals (perfect for mixing desk - and the output is in-phase with the input). Bypass is now done electronically with a strong stomp switch and silent operation. The Micro runs off either an internal 9v battery or standard Boss-style DC Jack (2.1mm centre negative 9v).

Here are some MP3 sound examples:
Clean electric guitar (straight to soundcard rather than through an amp)
Distorted electric ( with an MXR Disto+ clone before the Crusher)
TR606
Modular Wobbles

BugBrand Modular

Introducing the new and ever-growing sonic superpower.
Now running off solar power.

Page of further details

Fly Contact Mics

The quickest, simplest and cheapest means for recording acoustic and other sounds. Simply stick the contact mic onto a flat surface of the instrument and connect by jack to your mixer or other input. The mic transforms vibrations in materials into audio signals and, just as the positioning of an acoustic mic will affect the sound picked up, so the sound from the contact mic can be changed with different positioning.

These contact mics have been successfully used on instruments including: Violin, Viola, Cello, Dulcimer, Thumb Piano, Acoustic Guitar, Electric Guitar (gave a kind of Banjo sound.!.), Sitar, Cymbals, Drums. If you stick one on the floor and pass it through an Electro Harmonix Hog'sFoot pedal, you get a decent electronic kick drum sound.

Such devices have been around for many years and I claim no part in their invention. It is pretty easy to make them yourself, but for those who don't want to solder, you can also buy them cheaply from the BugBrand Shop. I've made a good few thousand of these over the years...

Click to enlarge

The iDEALIST Drone Machine

BugBrand Drone Machine
Not generally available! Five have been built - one kept for personal use.
No More! No More!

Looking a bit like a box for make-up, the new Drone Machine is powerful-but-portable fully modular synth and processing device in a compact carry case.

Featuring:

• Audio input with Envelope Follower - input preamp with variable decay envelope follower (EnvFlw based on SynTom ideas)
• Ring Modulator - using the AD633 multiplier chip
• 3 x Voltage Controlled Oscillators (plus Low Freq Osc) - three powerful VCOs (based around the Thomas Henry XR2206 VCO) that can also run at low freqs for modulation, offering tri / sin / sqr waveforms, plenty of modulation and sync function.
• Voltage Controlled Filter - state variable (Lo / Band / Hi response) resonant filter with modulation and two audio inputs
• Digi-delay - based around the PT2399 digital delay chip that can be cranked down into very noised-up territories.
• 2 x Voltage Inverters - for audio or CVs
• Output Mixer - 3 channels mixed to mono output

All connections, other than input / output, are on 4mm banana plugs which open up a vast array of connective potential. Powered by a 12V AC adaptor.

Prototype built June 06 - this will not be going into full production!

All the background work on the BugBrand Modular has provided me with loads of new techniques and inspiration. It is now possible to begin making small custom systems squeezing bunches of sonic-power into compact devices.

The desire here was to make a small analogue sound & processing system to fit into some metal slope-fronted cases I got hold of.

The system contains:

• Input Mixer - Audio Input Preamp, Noise Source, Extra Channel
• VCOs x 2 - Lofi Voltage Controlled Oscillators with audio or lfo rates producing vari-shape Tri / Sqr waveforms - certainly no 1v/oct tuning here!
• State-variable VCF - Voltage Controlled Filter with Lo / Band / Hi - pass responses and variable resonance (up to screamy self-oscillation)
• Output Mixer - two channel output mixer
• Ring Modulator - AD633 type with modulation option
• Attenuverter - signal level control and inverter
• Foot Control - CV generator from volume pedal with adjustable range

All housed in a bright red slope-fronted metal case measuring about 25 x 20cm.

All connections are 4mm banana patch plugs apart from 1/4" for Audio Input & Output and Foot Control.

The box runs off a 12 AC adaptor to give a +/- 12v Bipolar Supply.

Demo1 - using the oscillators & filter - cross & self modulation
Demo2 - noisy microphone processing, screamy towards the end
Demo3 - tr505 through the box
Demo4 - guitar processing - from tremolo to ringmod with foot control
(pretty rough'n'ready demo sounds.!. and largish mp3 files...)

BugCrusher Production

BugCrusher Controls

BugCrusher Prototype June 06

BugBrand BugCrusher - Audio rate Sample&Hold for BitCrush effects
The first batch of 15 BugCrushers is all sold out

The BugCrusher is a Sample Rate Reducer pedal that uses audio-rate sample&hold to give a bit-crusher style effect. Other than a few digi-multi-effects, there is only one other hardware effect similar to this in the world - the Frostwave Sonic Alienator - we do things a bit differently, but give quite similar results.

You can plug many different things into the BugCrusher - connections are on 1/4" mono jacks. The active preamp brings whatever signal up to suitable levels and can be slightly overdriven for extra crunch. Adjust the RateReduce knob to change from full-rate/no-effect though fizzly high-end and down into sonic murk that sounds similar to a ring-mod but with a bit more clarity.

There's a modulation LFO (low freq oscillator) to modulate the SampleRate - with its own depth control, this gives variable shaped triangle or square wave modulation at speeds from slow (about 20seconds per cycle) to fast (about 20 cycles per second). The waveshape control changes the triangle shape from ramp through triangle to sawtooth or changes the pulse-width of the square waveform.

There's also a foot control input with depth control. Attaching a suitable volume pedal allows you to change the SampleRate with your foot - great for playing. And this socket can also act as an external CV input if you want to modulate the sample rate with CVs from, for example, a modular synth.

The BugCrusher is built into a mighty strong aluminium enclosure and uses the industry standard superstrong EH3PDT stomp switch for bypass. This is not TrueBypass - the audio signal still passes through the preamp when the RateReduce is bypassed, but the preamp imparts no change in tone. Why like this? Because the BugCrusher runs signals at higher levels than most stomp pedals ('cos its synth-based)

The pedal is designed on a modular-synth basis and so has special power requirements - the BugCrusher requires an 12VAC adaptor (AC not DC) and won't run off batteries. All BugCrushers come with an AC adaptor - UK, Euro and US version AC adaptors are all now available.

So, that's all good&techy, but how does it sound? Here's a bunch of demonstrations:
Overdrive TR606
Short Guitar Burst
Guitar
TR505 drum-machine
Voice
Whistling

If you're a techy person there's full schematic details on the Electronics Page so you can build one yourself!

Click to enlarge

BugBrand BabyBugCrusher - v1

The BabyBugCrush is a simplified version of the BugCrusher Pedal - the LFO modulation and foot control have been sliced off to keep the design simple but effective - delivering the lovely BugCrushing sounds but in a more compact box and at a lower price.

• Input Preamp - suitable for guitar / microphone at high gain levels or can be set to a low level for use with line-level signals.
• Sample Rate (the big knob) - sets amount of crushing from zero effect (fully clockwise) through high-end fizzle and down to total sonic murk.
• Output Level - the BabyBugCrush can provide a great deal of gain to the signal - this is ideal for mixing desk applications, but will also work fine for guitar setups if the output level is kept relatively low.
• InPhase output - the output signal (whether effected or bypassed) is in phase which means the pedal can be easily used as a mixing desk effect send.
• Bypass - this pedal is not true bypass - the signal still passes through the preamp when bypassed. The strong bypass stomp switch provides totally silent switching.
• 1/4" mono jack input & output.
• AC powered - supplied with a choice of UK, Euro or US AC power adaptor.

BabyBugCrusher demo mp3 - starts off clean and then highlights the phasing tones of heavy crushing (on decent speakers you'll hear the super lo-freqs) before moving to high-end-fizzle settings.

Instruction Manual (pdf)

Click to enlarge

Weevil07
Very limited quantities so far...

Yet further mutations to the Weevil family.. The new design again features twin ring-modulated oscillators, but these now have pulse shaping and improved power-starve operation, along with a filter upgraded to a resonant low-pass design.

More touchy, more screechy!

Weevils 2006
..now updated to Weevil07..

The Weevil circuitry continues to mutate and adapt. This current design features twin ring-mod lofi oscillators connected to a massive copper touch-plate and it loves to click, drone and squeal. Bend the sound in supr-extreme manners with the 8 copper contact elements - lick your fingers and allow the electrons to flow via your body, causing the oscillators to wail and fight each other. The low-power knob starves the battery supply, simulating a battery running out and leading to wonderful sonic circuit malfunctions. Now with an added tone/filter control for extra sonic powers.

Some Weevils are now sporting joystick controllers.

IconsWeevil - batch of 5 to celebrate the ICONs Exhibition
MetakWeevil - bacth of 8 for the wonderful Sound Metak shop in Milan, Italy
iDEALWeevil - one off for the hyper iDEAL Records of Gothenburg, Sweden
NoiseFXWeevil - batch of 3 for San Francisco noise merchants NoiseFX

Devices can be made to order with customised touchplates.

Sounds of the ICONsWeevil (mp3 - 4.63MB)
Sounds of the JoyWeevil (mp3 - 6.79Mb)

Video of the JoyWeevil (avi - 30MB) - this should work fine in Quicktime..
This shows a bit how the sounds respond to controls / touch / joystick wobbling (though I forgot to change to Lo-pitch-range).

Instruction Manual (pdf)

AudioWeevil06
..AudioWeevil07 coming soon..

Finally we've got a decent audio input into the chaotic heart of the Weevil - you want screamy audio processing? The AudioWeevil06 turns your input signal into a squarewave which can then be modulated with one of the internal oscillators for hyper-harsh ringmod or distortionary tremelo effects.

This design may well transform into a stomp pedal too...

Instruction Manual (pdf)

PostcardWeevil07
Released late Aug07

The new PWeevil adds a further oscillator and ringmod to the mix along with, for the first time in PWeevils, a mini-jack output. This is the affordable entry into Weevil world, presented in a compact circuit for on-the-move noise-making. Clicks, warbles, squeaks and screams, plus 9 body contacts!

Lofi recording from the output mp3 - taken straight into a latop mic input jack.
Squealy chirrups!

See also PostcardWeevilV2

Postcard Weevil v2
The PostcardWeevil is a hyper-portable noise making device. The design was first made for the Euro-travel tour of 2005 and has now been updated with the addition of three tiny dials for a load of extra sounds.

Like other Weevils, the Postcard has two lofi oscillators that are ring-modulated together. Each osc has a pitching dial and body contact points to pitch and bend the tones. The final dial is for low-power - it reduces the power supply to the osc chips so they malfunction into wondrous sonic territories.

The Postcard runs off a 9v battery and has a pretty loud little speaker. What, no line output? Well, this was a design choice, but you can hold the speaker up to a microphone or close to a guitar pickup (magnetic type). You can also try placing the speaker by your open mouth and adjusting the shape of your mouth to give vowel sounds.

Instruction Manual (pdf)

Here Shop Weevil
Weevil2006 with internal Amp&Speaker for on-the-move noising.

Now on permanent display at the very wonderful Here Shop in Bristol.

The Here Shop is a lovely place on Stokes Croft that sells craft, comics, stuff and has an exhibition space downstairs. Its the only regular stockist of BugBrand Contact Mics too.

The first few Weevils...
A unique mix of digital and analogue circuitry, a wide array of different controls and a heap of circuit bends, make the Weevil a chaotic and noisy, but highly playable instrument.

The Weevil is now a year old and in that time over a dozen instruments have been built, spreading out to live all around the world. Each new one further mutates the original design, adding new features and trying out different interface layouts.

The heart of a Weevil
The Weevil is based around two identical sections mirrored down the centre of the box.

Each section features two square wave oscillators that are ring-modulated together - these are built around digital chips, but controlled in an analogue manner for endless variation. In each section one oscillator is controlled simply by a knob, while the other is switchable between knob or light sensor. Points in each oscillator circuit are connected to body contact points - touch then with you fingers or other body parts for pitch bends and growls - and momentary buttons cross the signals between the sections for further crashes.

The sections each have simple punch in/out buttons before the two are mixed together and scream outwards to greet the world with sounds ranging from chordal drones to crashing modems, deep-bass-rumbles to shortwave radio interference.

Original Weevil: Extract1, Extract2, Extract3, Extract4, Extract5
Weevil2: Extract1, Extract2, Extract3, Extract4, Extract5
Weevil Extreme: Long Recording (20Mb)
Weevil Industrial Slope: Extract1, Extract2, Extract3

Some people currently using Weevils:
Monolab(UK), AudioBell(Sweden), SPBaker(Australia), Rarg (UK)

Weevil Knievel 2

A repro. Weevil Knievel tweaked into even better territories and covered in no-less than 23 body contacts for super-squirmy touch-noises. The LFO filter modulation has been mightily improved from the original Knievel too.

Built for Sean Gas Shepherds who currently plays in the Broadcast live band.

Audio Weevil

Digi-ringmodulation with audio input (first time on a digi-weevil).

The box can function either as a sound synthesiser (without audio input) for traditional (ha!) Weevil sounds, or you can, in a pretty chaotic way, pass audio into it for serious sound mangles - the audio input is turned into a squarewave that is then quasi-ring-modulated by the two internal squarewave oscillators.

The top of the box takes some serious nods at the Cracklebox - 8 large body-contact touch pads that really bend and warp the sound for great hands-on playability.

Sound Example (1.77Mb) (note: this is an example without audio input)

Weevil Saxophone

Two Weevil Saxophones were built for the Swedish players Mats Gustafsson and Dror Feiler in April 2005.

The saxes act as controllers/modifiers filled with sensors (body contacts, pressure sensors, triggers and a microphone) and hooked up to aluminium carry cases packed full of electronic circuits (ring mods, filters, VCAs, LFOs, envelope followers, audio inputs).

Page of further details

Weevil Knievel

Given the name Knievel due to its lurid blue colour remeniscent of the death-defying biker.

Again making use of ring-modulated oscillators, but this time with a total of 6 oscs with one global pitch control (and body contacts for each osc). Add to this a state-variable filter (low/band/high-pass with resonance) and a modulation LFO and you've got shreeking audio from high to low.

Sound Example (2.09Mb)

Mecha Weevil

The two Mechas that were built combined Weevil sound circuitry with additional drum-style envelope amplifiers (piezo triggered) in a strong metal case. The result? An even more versatile Weevil which can function as two channel drum synth.

In use by Lasse Marhaug

Sound Examples: Extract1, Extract2, Extract3, Extract4, Extract5, Extract6

Weeviliser

An all analogue ring-modulator pedal that also manages to do tremolo. Square & Triangle modulation waveforms (with variable frequency and waveshape), plus an input overdrive circuit and output tone control. All squeezed into a pint sized metal case with serious stompability.

Sound Example (2.93Mb)

WeevilFrame

Postcard Weevils mounted into picture frames with custom designed touchplates for unique sonic arts.

Sound Example (746kb)

New sounds through malfunction. Open up an electronic device (such as kid's keyboard, cheapy drum machine, etc) and probe about making short circuits until the device starts garbling streams of new sounds. You can also add body contacts - metal bits (such as screws) that attach to points of the circuit and, when touched by fingers, create changes such as pitch bends and growls. If you really experiment you can also add extra electronic components such as resistors (especially variable and light dependent resistors), capacitors, etc.

There is a lot of info around on the internet (some links on the resources page), but the best way is just to get something and experiment (warnings: Only ever circuit bend battery powered devices and don't go trying an expensive bit of gear straight off because things can be broken).

Many of the techniques of circuit bending have filtered into the designs of BugBrand sound devices.

Yamaha VSS30

The VSS30 is probably the best 'kiddie' sampling keyboard - it's features, even without circuit bending, provide a great instrument with 4 note sampling polyphony, looping (with loop length and reverse), ADSR envelope and various effects. All of these can be instantly assigned and modified.

These circuit bends only change the sampled voice, some permanently modifiying the sample (degrading it, chopping it, adding noise and distortion), while others are momentary effects.

All bends are achieved by attacking the sampling chip within the keyboard. This offers something like 100+ possible bends, so I selected the best ones and attached momentary buttons to them (you could use a patchbay instead). Because there isn't much panel space for mounting extra buttons, I chose to bolt an extra plastic case onto the side to house the buttons. I haven't done anything to make it look pretty yet..

Sound Example

Yamaha DD-6

Hyper-mods! When you start playing with the digital chips of drum machines there are SO many possible mods that you'd go mad trying to wire up switches for everything. So making a patchable instrument is the way. Where other people use phono or jack sockets, I prefer the quick&simple 4mm banana plugs (as used in my modular system) - they're really quick to use, cheap, colourful and it takes a fraction of the time to make the cables (no soldering and no ground connection).

This one has 27 connection points plus 4 momentary buttons for patching in. That makes for something like 13,745,882 possible configurations......

Yamaha TR505

Makes some good sounds but the really interesting/useful thing is that it has MIDI in/out so it can sync to other devices.

I wasn't all that methodical about choosing the bends - just attack the insides and messy/noisy sounds will result.!. The 6 switches are double-pole centre-off, so each one offers two different bends.

Realistic SessionMate

A cheesy drum machine with a variety of onboard backing tracks. With only two momentary buttons and a switch this machine has been transformed into something that spits out instant greatness ranging from Max Tundra style musics to minimal electronics and destructionary noises.

Sound Example 1, Sound Example 2

Yamaha DD-7 Super Session Player

My first drum machine, my first bending project, and still one of the finest (..dirtiest..) sounding machines I have modified. The internal sounds are a bit lame, but with the 6 switches and 3 momentary buttons, it is transformed into an evil and raw ripping machine.

Sound Example 1, Sound Example 2, Sound Example 3

TI Speak Family

Speak & Spell, Super Speak & Spell, Speak & Maths and Speak & Read.
Each with a variety of bends including glitching, looping, pitching, plus reset and 1/4" jack output.

These were all modified, one by one over about a year, for Lars Westin.

TI Speak & Spell

Probably the commonest device for circuit bending, I've done a variety of these with mods such as pitch up & down, looping, glitches, body contacts, light dependents. There are always loads of possibilities within...

Sound Example 1, Sound Example 2, Sound Example 3

TI Speak & Maths

I've done a couple of these too and it seems to give better results than the S&S. Wonderful changeable rhythmic beats.

Sound Example 1, Sound Example 2, Sound Example 3

TI Touch & Tell

A much bigger device with interchangeable activity cards giving various ranges of words. Glitch and loop buttons mess the internals.

Sound Example 1, Sound Example 2, Sound Example 3
T&T All Black Edition - Sound Example 1, Sound Example 2

The following MIDI control devices have been made using the Doepfer Pocket Electronics Kit, an affordable 16-channel MIDI brain (ready built). You only need to connect some controls (buttons, dials, switches - or electronic circuits) and out comes a wide variety of MIDI signals. Its a pretty damn good basis for making custom MIDI controllers.

Control Rack

A 1u rackmount interface with various control units that plug in to it. This was built because I've not been able to find a suitable MIDI foot control device for live shows.

• 2 sets of four momentary footswitches
  - with locking circular multipole connections
• connection for 4 volume pedals
  - one of these can also function as a program selector
• remote hand control with 3 knobs and a ribbon controller

Its a fairly lofi construction - more to do the job than to look pretty. A future improvement will be to add a circuit that allows the footswitches to function electronically as momentary or latching switches.

Sonic Post - ICONs Controller

The Sonic Post was built for the ICONs Exhibition at the start of 2006.

This interface investigated several electronic forms, coupled with copper touch plates, for driving the Pocket Electronics.

• Four Analogue LFOs (Left-hand side figure) running at slow speeds and producing a voltage range of 0 to +5v. The LFOs can be sped up by touching points on the figure (effectively reducing a resistance in the LFO circuitry)
• Eight Momentary Electronic Touch Switches (centre squares).
  Based on Paia designs
• Four Touch-voltage followers (Right-hand side figure). These sit at zero volts when untouched and rise in value dependent on the pressure of touching.

The MIDI controller was mounted inside a large wooden case which also held a Nord MicroModular (controlled by the MIDI signals), two amps and two speakers.

Headphone Line Mixer

Custom build for The Hatch Studio.

Designed to take 16 line levels and mix four independent headphone mix outputs. Compact (2U rack) and efficient!

SN76477 Cigar Box Synth

A mutant stylophone built from plans in an old german electronics magazine.

50 - 60 Hz Sine Wave Generator

A pure waveform generator limited to the range of 50 to 60 Hz for drone tone and vibration experiments.

Lofi Looper
Development of this was looking really promising, but the design still gave problems (bad ones, not just wierd'n'fun sounds) - so it seems to be put on permanent hold. URGH.

Sometime quite a while ago I began working on an update to the Dirty Sampler and only now do I feel it is nearing completion - there have been lots of little niggles to figure out. This can be seen as pre-release info.

The LofiLooper is built around a voice recorder chip that's really designed for applications such as answering machines - it is low resolution and low fidelity. By adding control circuitry and a bunch of knobs & switches it is possible to get some mighty interesting results - record up to 16secs of sound in, play it back, loop it, repitch it, rhythmically randomise it...

There's quite a lot going on:

• Preamp / Mix Section - plug in your guitar or similar sound source around the back. The preamp brings the signal up to a suitable level and you set the Rec Level into the sampling chip, the Dry Feedthrough Level and the Wet Playback Level.
• Control Section - Fine and Coarse Tune knobs for repitching and Auto-gate speed knob.
• Modes - Loop loops the entire sample. Conc allows you to combine several short recordings into one long sample (normally, each recording by default resets to the start of sample memory). Rand is the randomised mode - each time playback is started (for example using the AutoGate) the device jumps to random position within the sample memory. The Random Range 3-way control selects the area of memory for randomisation
• Rec / Play - Momentary buttons plus footcontrol (you can use button or footswitch at the same time). The playback also has a toggle switch to Hold the playback (continuous playback - but will only loop if the mode is set to Loop) or connect the Auto-Gate. The gate can also be switched between stuttery Stacatto setting (for more pronounced rhythm) or Legato. There are 0-5v gate inputs on the back of the unit for standard modular synth gating of the record and playback functions
• Power - the unit runs off a single 9v battery located in a drawer at the back of the box (a DC input could also be added).

By altering the Speed controls you can tune the sample over about 2 octaves range and this also changes the available recording time . You can record when set at a lower speed, but then the loop point can glitch/stutter a bit so loops are more difficult to do right.

Sounds:
Using the Conc Mode and repitching with a musicbox (1.62MB) - notes are sampled first with the Tune set really low which gives a real crunch to the sounds. They are then pitched way up before further notes are sampled.
Philicorda Organ sounds being randomised (3.18MB) - a drone is recorded to fill the memory space - tuning is set quite low so that the sample can then be pitched up. Randomisation is kicked in around 40seconds - the organ drone continues with the rhythmics coming from the AutoGate randomised playback.

Harsh Noise Purity

A pedal with 2-input mix, noise generator and active feedback loop that is followed by two Rat distortion clones in series.

Weeviliser Extreme

A Weeviliser analogue ringmod pedal with added resonant filter.

Princeton Supra

A custom built dual overdrive stomp box which emulates the sounds of two classic Fender valve amps, the Princeton and the Supra.

Built with schematics from Runoffgroove.

Cracklebug

Bug-themed version of the classic Cracklebox (see below). With its own internal speaker for crazed body contact noises, the design also adds an output jack (with volume control) and low power knob (simulates the battery running out for extra sound possibilities).

Produced in a limited run of 8 devices.

Cracklebox Clone

The original Cracklebox was built in the 1970s by Michel Waisvisz of Steim and is surely the grandparent of all circuit bent devices.

Sound Example 1 Sound Example 2

Filter Boxes
An all analogue processing box running off two 9v batteries and combining:

• Resonant VC Filter, switchable between low-pass & band-pass.
• VCA
• Envelope Generator with piezo trigger for filter/VCA modulation.
• Vari-speed triangle LFO for filter/VCA modulation

Sound Examples (processing the named signals):
Acoustic Guitar, LightOsc - Low wave bubbles, Light Osc - Trigger Operation, Light Osc - Body Contact Operation, Ride Cymbal

Lepidoptera Light Oscillators
There have been a variety of different light dependent oscillators built by BugBrand. The amount of light falling on the LDR sensor determines the pitch, with bright light giving high pitches and darkness giving low rumbles. Always great fun for special effects or big drones.

Baby Lepidoptera - A perfect size to sit in your hand with your thumb positioned to bridge between the brass body contacts for warbling pitch bends. Hi & Lo pitch ranges.
Sound Example

Lepidoptera Pillarbox - Three different pitch ranges, tone controls and an internal speaker.
Sound Example

Dual Sampler

An audio signal of up to about half a minute can be recorded onto the box's two lo-fidelity sampling chips. Samples can then be played back as loops and pitched either with a knob or with body contact points. The dual chips allow the same sample to be recorded onto both chips at the same time so that phasing playback can be initiated, and you can also join multiple short bursts of recording together into one big sample.

Sound Example 1 (with acoustic guitar) Sound Example 2 (with throat mic)

Dual Envelope Amplifier

Two Voltage Controlled Amplifiers (VCAs) each controlled by a fast-attack, variable-decay (up to about 2 seconds) envelope generator. The envelope can be triggered by velocity sensitive piezo contact (internal or external) or standard sequencer trigger signals. A continuous sound is fed into the audio input and, on triggering of the envelope generator, bursts of sound are let through to the audio output.

Dirty Sampler

Super-lo-fi, quick and easy sampler with looping and repitching. Built around a chip that offers 16 seconds of 8KHz recording, samples are imparted with a crunchy sound quality not found on any commercial sampler.

Sound Example (with Slinky sound source)

Chocolate Cake

Howling tones of feedback and light dependency.

Sound Example